We have a vinyl in-ground pool that we've owned for about six months but only started using in the last couple. We live in Victoria, Australia so not too cold in the winter but we had winterised the pool based on the advice of a pool guy we hired when we first moved in. The previous owner also left quite a lot of solid chlorine in the filter basket before they left (not recommended from what I'm reading here). I left the pool maintenance to my husband but as I've started tho read more I realise that he hasn't really read up on the finer details.
Anyway the pool looks great but our test strips show we have no free chlorine and quite high combined chlorine. I bought some bleach to do a SLAM but it has no percentage on it and we don't have a test kit that will give us more sensitive results than the Aquachek 7 in 1 that we're using now. I'm also unsure as to our CYU levels. It continuously comes up in the 30-50 range - this is apparently in the ideal range but is somewhat imprecise. Also we haven't added stabiliser since we've been here - is it normal for CYU levels to stay the same for a long period of time or do you lose some? I'm cautious of adding more since it seems that it's very hard to remove if you add too much.
The pool is somewhere in the realms of 30,000 to 40,000 litres. Its hard to work out due to the slope around the deeper parts of the pool. We plan to measure and draw it up this weekend.
From the last test strip we had:
Total hardness: 100 very low - I read that hardness is not relevant in vinyl pools - right?
Total chlorine - swings between 0.5 and 3 depending on whether we've remembered to add chlorine the day before.
Free chlorine - sitting at 0 for the last few months
pH - generally in the 7.2 to 7.8 range
total alkalinity s generally in the okay range about 160. However I read here that vinyl pools should have a higher alkalinity - is that right?
CYU - 30-50 range.
So basically quite confused but it seems that a SLAM is in order to restore the FC. I just don't know how much to add. Can I do a temporary fix for christmas then sort it out properly afterwards by chucking a load of bleach in tonight??
In the longer term what's the easiest way to add chlorine every day without doing it manually?
Also we have a hole in the corner of the vinyl which my husband patched (badly). The pool guy that came at the beginning said we had a good ten years of life left in the liner. The hole may have been smaller then! Do you get a professional in for these sort of fixes ? Especially considering he needs to remove the current messy patch.
Thanks for all your help.